Results of subgroup analyses
| Reason for subgroup analyses | Pooled results of subgroups | Heterogeneity of subgroups | ||
| SMD/RR (95% CI) | I2 (%) | P values | ||
| Pain | ||||
| Location | Knee OA | −0.54 (−1.04 to 0.04) | 88 | 0.03 |
| Cervical OA | −2.33 (−6.26 to 1.61) | 97 | 0.25 | |
| Hand OA | −2.85 (−3.65 to 2.04) | NA | <0.00001 | |
| Exposure duration | No more than 0.5 hour/session | −1.01 (−1.64 to 0.39) | 91 | 0.001 |
| More than 0.5 hour/session | −0.61 (−2.25 to 1.02) | 95 | 0.46 | |
| Function | ||||
| Location | Knee OA | −0.34 (−0.53, to 0.14) | 0 | 0.0006 |
| Cervical OA | −0.27 (−0.71 to 0.16) | NA | 0.22 | |
| Hand OA | −1.49 (−2.12 to 0.86) | NA | <0.00001 | |
| Exposure duration | No more than 0.5 hour/session | −0.50 (−0.81 to 0.18) | 59 | 0.002 |
| More than 0.5 hour/session | −0.33 (−0.82 to 0.17) | 54 | 0.20 | |
| Adverse event | ||||
| Exposure duration | No more than 0.5 hour/session | 0.42 (0.14 to 1.29) | 0 | 0.13 |
| More than 0.5 hour/session | 1.95 (0.81 to 4.71) | NA | 0.14 | |
NA, not available.; OA, osteoarthritis; RR, relative risk; SMD, standard mean difference.